// Modified version of DirectXTK12's source file

//--------------------------------------------------------------------------------------
// File: DDSTextureLoader.cpp
//
// Functions for loading a DDS texture and creating a Direct3D runtime resource for it
//
// Note these functions are useful as a light-weight runtime loader for DDS files. For
// a full-featured DDS file reader, writer, and texture processing pipeline see
// the 'Texconv' sample and the 'DirectXTex' library.
//
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
//
// http://go.microsoft.com/fwlink/?LinkID=615561
//--------------------------------------------------------------------------------------

#include <assert.h>
#include <algorithm>
#include <memory>
#include <wrl.h>

#include "DDSTextureLoader.h" 
#include "DDS.h"

using namespace Microsoft::WRL;

#if !defined(NO_D3D11_DEBUG_NAME) && ( defined(_DEBUG) || defined(PROFILE) )
#pragma comment(lib,"dxguid.lib")
#endif

using namespace DirectX;

//--------------------------------------------------------------------------------------
// Macros
//--------------------------------------------------------------------------------------
#ifndef MAKEFOURCC
#define MAKEFOURCC(ch0, ch1, ch2, ch3)                              \
                ((uint32_t)(uint8_t)(ch0) | ((uint32_t)(uint8_t)(ch1) << 8) |       \
                ((uint32_t)(uint8_t)(ch2) << 16) | ((uint32_t)(uint8_t)(ch3) << 24 ))
#endif /* defined(MAKEFOURCC) */

//--------------------------------------------------------------------------------------
namespace
{

	struct handle_closer { void operator()(HANDLE h) { if (h) CloseHandle(h); } };

	typedef public std::unique_ptr<void, handle_closer> ScopedHandle;

	inline HANDLE safe_handle(HANDLE h) { return (h == INVALID_HANDLE_VALUE) ? 0 : h; }

	template<UINT TNameLength>
	inline void SetDebugObjectName(_In_ ID3D11DeviceChild* resource, _In_ const char(&name)[TNameLength])
	{
#if defined(_DEBUG) || defined(PROFILE)
		resource->SetPrivateData(WKPDID_D3DDebugObjectName, TNameLength - 1, name);
#else
		UNREFERENCED_PARAMETER(resource);
		UNREFERENCED_PARAMETER(name);
#endif
	}

};

//--------------------------------------------------------------------------------------
static HRESULT LoadTextureDataFromFile(_In_z_ const wchar_t* fileName,
	std::vector<uint8_t>& ddsData,
	DDS_HEADER** header,
	uint8_t** bitData,
	size_t* bitSize
)
{
	if (!header || !bitData || !bitSize)
	{
		return E_POINTER;
	}

	// open the file
#if (_WIN32_WINNT >= _WIN32_WINNT_WIN8)
	ScopedHandle hFile(safe_handle(CreateFile2(fileName,
		GENERIC_READ,
		FILE_SHARE_READ,
		OPEN_EXISTING,
		nullptr)));
#else
	ScopedHandle hFile(safe_handle(CreateFileW(fileName,
		GENERIC_READ,
		FILE_SHARE_READ,
		nullptr,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		nullptr)));
#endif

	if (!hFile)
	{
		return HRESULT_FROM_WIN32(GetLastError());
	}

	// Get the file size
	LARGE_INTEGER FileSize = { 0 };

#if (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
	FILE_STANDARD_INFO fileInfo;
	if (!GetFileInformationByHandleEx(hFile.get(), FileStandardInfo, &fileInfo, sizeof(fileInfo)))
	{
		return HRESULT_FROM_WIN32(GetLastError());
	}
	FileSize = fileInfo.EndOfFile;
#else
	GetFileSizeEx(hFile.get(), &FileSize);
#endif

	// File is too big for 32-bit allocation, so reject read
	//if (FileSize.art > 0)
	{
		//	return E_FAIL;
	}

	// Need at least enough data to fill the header and magic number to be a valid DDS
	if (FileSize.LowPart < (sizeof(DDS_HEADER) + sizeof(uint32_t)))
	{
		return E_FAIL;
	}

	// create enough space for the file data
	ddsData.resize(FileSize.LowPart);
	//ddsData.reset( new (std::nothrow) uint8_t[ FileSize.LowPart ] );
	//if (!ddsData)
	//{
	//    return E_OUTOFMEMORY;
	//}

	// read the data in
	DWORD BytesRead = 0;
	if (!ReadFile(hFile.get(),
		ddsData.data(),
		FileSize.LowPart,
		&BytesRead,
		nullptr
	))
	{
		return HRESULT_FROM_WIN32(GetLastError());
	}

	if (BytesRead < FileSize.LowPart)
	{
		return E_FAIL;
	}

	// DDS files always start with the same magic number ("DDS ")
	uint32_t dwMagicNumber = *(const uint32_t*)(ddsData.data());
	if (dwMagicNumber != DDS_MAGIC)
	{
		return E_FAIL;
	}

	auto hdr = reinterpret_cast<DDS_HEADER*>(ddsData.data() + sizeof(uint32_t));

	// Verify header to validate DDS file
	if (hdr->size != sizeof(DDS_HEADER) ||
		hdr->ddspf.size != sizeof(DDS_PIXELFORMAT))
	{
		return E_FAIL;
	}

	// Check for DX10 extension
	bool bDXT10Header = false;
	if ((hdr->ddspf.flags & DDS_FOURCC) &&
		(MAKEFOURCC('D', 'X', '1', '0') == hdr->ddspf.fourCC))
	{
		// Must be long enough for both headers and magic value
		if (FileSize.LowPart < (sizeof(DDS_HEADER) + sizeof(uint32_t) + sizeof(DDS_HEADER_DXT10)))
		{
			return E_FAIL;
		}

		bDXT10Header = true;
	}

	// setup the pointers in the process request
	*header = hdr;
	ptrdiff_t offset = sizeof(uint32_t) + sizeof(DDS_HEADER)
		+ (bDXT10Header ? sizeof(DDS_HEADER_DXT10) : 0);
	*bitData = ddsData.data() + offset;
	*bitSize = FileSize.LowPart - offset;

	return S_OK;
}


//--------------------------------------------------------------------------------------
// Return the BPP for a particular format
//--------------------------------------------------------------------------------------
static size_t BitsPerPixel(_In_ DXGI_FORMAT fmt)
{
	switch (fmt)
	{
	case DXGI_FORMAT_R32G32B32A32_TYPELESS:
	case DXGI_FORMAT_R32G32B32A32_FLOAT:
	case DXGI_FORMAT_R32G32B32A32_UINT:
	case DXGI_FORMAT_R32G32B32A32_SINT:
		return 128;

	case DXGI_FORMAT_R32G32B32_TYPELESS:
	case DXGI_FORMAT_R32G32B32_FLOAT:
	case DXGI_FORMAT_R32G32B32_UINT:
	case DXGI_FORMAT_R32G32B32_SINT:
		return 96;

	case DXGI_FORMAT_R16G16B16A16_TYPELESS:
	case DXGI_FORMAT_R16G16B16A16_FLOAT:
	case DXGI_FORMAT_R16G16B16A16_UNORM:
	case DXGI_FORMAT_R16G16B16A16_UINT:
	case DXGI_FORMAT_R16G16B16A16_SNORM:
	case DXGI_FORMAT_R16G16B16A16_SINT:
	case DXGI_FORMAT_R32G32_TYPELESS:
	case DXGI_FORMAT_R32G32_FLOAT:
	case DXGI_FORMAT_R32G32_UINT:
	case DXGI_FORMAT_R32G32_SINT:
	case DXGI_FORMAT_R32G8X24_TYPELESS:
	case DXGI_FORMAT_D32_FLOAT_S8X24_UINT:
	case DXGI_FORMAT_R32_FLOAT_X8X24_TYPELESS:
	case DXGI_FORMAT_X32_TYPELESS_G8X24_UINT:
	case DXGI_FORMAT_Y416:
	case DXGI_FORMAT_Y210:
	case DXGI_FORMAT_Y216:
		return 64;

	case DXGI_FORMAT_R10G10B10A2_TYPELESS:
	case DXGI_FORMAT_R10G10B10A2_UNORM:
	case DXGI_FORMAT_R10G10B10A2_UINT:
	case DXGI_FORMAT_R11G11B10_FLOAT:
	case DXGI_FORMAT_R8G8B8A8_TYPELESS:
	case DXGI_FORMAT_R8G8B8A8_UNORM:
	case DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
	case DXGI_FORMAT_R8G8B8A8_UINT:
	case DXGI_FORMAT_R8G8B8A8_SNORM:
	case DXGI_FORMAT_R8G8B8A8_SINT:
	case DXGI_FORMAT_R16G16_TYPELESS:
	case DXGI_FORMAT_R16G16_FLOAT:
	case DXGI_FORMAT_R16G16_UNORM:
	case DXGI_FORMAT_R16G16_UINT:
	case DXGI_FORMAT_R16G16_SNORM:
	case DXGI_FORMAT_R16G16_SINT:
	case DXGI_FORMAT_R32_TYPELESS:
	case DXGI_FORMAT_D32_FLOAT:
	case DXGI_FORMAT_R32_FLOAT:
	case DXGI_FORMAT_R32_UINT:
	case DXGI_FORMAT_R32_SINT:
	case DXGI_FORMAT_R24G8_TYPELESS:
	case DXGI_FORMAT_D24_UNORM_S8_UINT:
	case DXGI_FORMAT_R24_UNORM_X8_TYPELESS:
	case DXGI_FORMAT_X24_TYPELESS_G8_UINT:
	case DXGI_FORMAT_R9G9B9E5_SHAREDEXP:
	case DXGI_FORMAT_R8G8_B8G8_UNORM:
	case DXGI_FORMAT_G8R8_G8B8_UNORM:
	case DXGI_FORMAT_B8G8R8A8_UNORM:
	case DXGI_FORMAT_B8G8R8X8_UNORM:
	case DXGI_FORMAT_R10G10B10_XR_BIAS_A2_UNORM:
	case DXGI_FORMAT_B8G8R8A8_TYPELESS:
	case DXGI_FORMAT_B8G8R8A8_UNORM_SRGB:
	case DXGI_FORMAT_B8G8R8X8_TYPELESS:
	case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB:
	case DXGI_FORMAT_AYUV:
	case DXGI_FORMAT_Y410:
	case DXGI_FORMAT_YUY2:
		return 32;

	case DXGI_FORMAT_P010:
	case DXGI_FORMAT_P016:
		return 24;

	case DXGI_FORMAT_R8G8_TYPELESS:
	case DXGI_FORMAT_R8G8_UNORM:
	case DXGI_FORMAT_R8G8_UINT:
	case DXGI_FORMAT_R8G8_SNORM:
	case DXGI_FORMAT_R8G8_SINT:
	case DXGI_FORMAT_R16_TYPELESS:
	case DXGI_FORMAT_R16_FLOAT:
	case DXGI_FORMAT_D16_UNORM:
	case DXGI_FORMAT_R16_UNORM:
	case DXGI_FORMAT_R16_UINT:
	case DXGI_FORMAT_R16_SNORM:
	case DXGI_FORMAT_R16_SINT:
	case DXGI_FORMAT_B5G6R5_UNORM:
	case DXGI_FORMAT_B5G5R5A1_UNORM:
	case DXGI_FORMAT_A8P8:
	case DXGI_FORMAT_B4G4R4A4_UNORM:
		return 16;

	case DXGI_FORMAT_NV12:
	case DXGI_FORMAT_420_OPAQUE:
	case DXGI_FORMAT_NV11:
		return 12;

	case DXGI_FORMAT_R8_TYPELESS:
	case DXGI_FORMAT_R8_UNORM:
	case DXGI_FORMAT_R8_UINT:
	case DXGI_FORMAT_R8_SNORM:
	case DXGI_FORMAT_R8_SINT:
	case DXGI_FORMAT_A8_UNORM:
	case DXGI_FORMAT_AI44:
	case DXGI_FORMAT_IA44:
	case DXGI_FORMAT_P8:
		return 8;

	case DXGI_FORMAT_R1_UNORM:
		return 1;

	case DXGI_FORMAT_BC1_TYPELESS:
	case DXGI_FORMAT_BC1_UNORM:
	case DXGI_FORMAT_BC1_UNORM_SRGB:
	case DXGI_FORMAT_BC4_TYPELESS:
	case DXGI_FORMAT_BC4_UNORM:
	case DXGI_FORMAT_BC4_SNORM:
		return 4;

	case DXGI_FORMAT_BC2_TYPELESS:
	case DXGI_FORMAT_BC2_UNORM:
	case DXGI_FORMAT_BC2_UNORM_SRGB:
	case DXGI_FORMAT_BC3_TYPELESS:
	case DXGI_FORMAT_BC3_UNORM:
	case DXGI_FORMAT_BC3_UNORM_SRGB:
	case DXGI_FORMAT_BC5_TYPELESS:
	case DXGI_FORMAT_BC5_UNORM:
	case DXGI_FORMAT_BC5_SNORM:
	case DXGI_FORMAT_BC6H_TYPELESS:
	case DXGI_FORMAT_BC6H_UF16:
	case DXGI_FORMAT_BC6H_SF16:
	case DXGI_FORMAT_BC7_TYPELESS:
	case DXGI_FORMAT_BC7_UNORM:
	case DXGI_FORMAT_BC7_UNORM_SRGB:
		return 8;

	default:
		return 0;
	}
}


//--------------------------------------------------------------------------------------
// Get surface information for a particular format
//--------------------------------------------------------------------------------------
static void GetSurfaceInfo(_In_ size_t width,
	_In_ size_t height,
	_In_ DXGI_FORMAT fmt,
	_Out_opt_ size_t* outNumBytes,
	_Out_opt_ size_t* outRowBytes,
	_Out_opt_ size_t* outNumRows)
{
	size_t numBytes = 0;
	size_t rowBytes = 0;
	size_t numRows = 0;

	bool bc = false;
	bool packed = false;
	bool planar = false;
	size_t bpe = 0;
	switch (fmt)
	{
	case DXGI_FORMAT_BC1_TYPELESS:
	case DXGI_FORMAT_BC1_UNORM:
	case DXGI_FORMAT_BC1_UNORM_SRGB:
	case DXGI_FORMAT_BC4_TYPELESS:
	case DXGI_FORMAT_BC4_UNORM:
	case DXGI_FORMAT_BC4_SNORM:
		bc = true;
		bpe = 8;
		break;

	case DXGI_FORMAT_BC2_TYPELESS:
	case DXGI_FORMAT_BC2_UNORM:
	case DXGI_FORMAT_BC2_UNORM_SRGB:
	case DXGI_FORMAT_BC3_TYPELESS:
	case DXGI_FORMAT_BC3_UNORM:
	case DXGI_FORMAT_BC3_UNORM_SRGB:
	case DXGI_FORMAT_BC5_TYPELESS:
	case DXGI_FORMAT_BC5_UNORM:
	case DXGI_FORMAT_BC5_SNORM:
	case DXGI_FORMAT_BC6H_TYPELESS:
	case DXGI_FORMAT_BC6H_UF16:
	case DXGI_FORMAT_BC6H_SF16:
	case DXGI_FORMAT_BC7_TYPELESS:
	case DXGI_FORMAT_BC7_UNORM:
	case DXGI_FORMAT_BC7_UNORM_SRGB:
		bc = true;
		bpe = 16;
		break;

	case DXGI_FORMAT_R8G8_B8G8_UNORM:
	case DXGI_FORMAT_G8R8_G8B8_UNORM:
	case DXGI_FORMAT_YUY2:
		packed = true;
		bpe = 4;
		break;

	case DXGI_FORMAT_Y210:
	case DXGI_FORMAT_Y216:
		packed = true;
		bpe = 8;
		break;

	case DXGI_FORMAT_NV12:
	case DXGI_FORMAT_420_OPAQUE:
		planar = true;
		bpe = 2;
		break;

	case DXGI_FORMAT_P010:
	case DXGI_FORMAT_P016:
		planar = true;
		bpe = 4;
		break;
	}

	if (bc)
	{
		size_t numBlocksWide = 0;
		if (width > 0)
		{
			numBlocksWide = std::max<size_t>(1, (width + 3) / 4);
		}
		size_t numBlocksHigh = 0;
		if (height > 0)
		{
			numBlocksHigh = std::max<size_t>(1, (height + 3) / 4);
		}
		rowBytes = numBlocksWide * bpe;
		numRows = numBlocksHigh;
		numBytes = rowBytes * numBlocksHigh;
	}
	else if (packed)
	{
		rowBytes = ((width + 1) >> 1) * bpe;
		numRows = height;
		numBytes = rowBytes * height;
	}
	else if (fmt == DXGI_FORMAT_NV11)
	{
		rowBytes = ((width + 3) >> 2) * 4;
		numRows = height * 2; // Direct3D makes this simplifying assumption, although it is larger than the 4:1:1 data
		numBytes = rowBytes * numRows;
	}
	else if (planar)
	{
		rowBytes = ((width + 1) >> 1) * bpe;
		numBytes = (rowBytes * height) + ((rowBytes * height + 1) >> 1);
		numRows = height + ((height + 1) >> 1);
	}
	else
	{
		size_t bpp = BitsPerPixel(fmt);
		rowBytes = (width * bpp + 7) / 8; // round up to nearest byte
		numRows = height;
		numBytes = rowBytes * height;
	}

	if (outNumBytes)
	{
		*outNumBytes = numBytes;
	}
	if (outRowBytes)
	{
		*outRowBytes = rowBytes;
	}
	if (outNumRows)
	{
		*outNumRows = numRows;
	}
}


//--------------------------------------------------------------------------------------
#define ISBITMASK( r,g,b,a ) ( ddpf.RBitMask == r && ddpf.GBitMask == g && ddpf.BBitMask == b && ddpf.ABitMask == a )

static DXGI_FORMAT GetDXGIFormat(const DDS_PIXELFORMAT& ddpf)
{
	if (ddpf.flags & DDS_RGB)
	{
		// Note that sRGB formats are written using the "DX10" extended header

		switch (ddpf.RGBBitCount)
		{
		case 32:
			if (ISBITMASK(0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000))
			{
				return DXGI_FORMAT_R8G8B8A8_UNORM;
			}

			if (ISBITMASK(0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000))
			{
				return DXGI_FORMAT_B8G8R8A8_UNORM;
			}

			if (ISBITMASK(0x00ff0000, 0x0000ff00, 0x000000ff, 0x00000000))
			{
				return DXGI_FORMAT_B8G8R8X8_UNORM;
			}

			// No DXGI format maps to ISBITMASK(0x000000ff,0x0000ff00,0x00ff0000,0x00000000) aka D3DFMT_X8B8G8R8

			// Note that many common DDS reader/writers (including D3DX) swap the
			// the RED/BLUE masks for 10:10:10:2 formats. We assume
			// below that the 'backwards' header mask is being used since it is most
			// likely written by D3DX. The more robust solution is to use the 'DX10'
			// header extension and specify the DXGI_FORMAT_R10G10B10A2_UNORM format directly

			// For 'correct' writers, this should be 0x000003ff,0x000ffc00,0x3ff00000 for RGB data
			if (ISBITMASK(0x3ff00000, 0x000ffc00, 0x000003ff, 0xc0000000))
			{
				return DXGI_FORMAT_R10G10B10A2_UNORM;
			}

			// No DXGI format maps to ISBITMASK(0x000003ff,0x000ffc00,0x3ff00000,0xc0000000) aka D3DFMT_A2R10G10B10

			if (ISBITMASK(0x0000ffff, 0xffff0000, 0x00000000, 0x00000000))
			{
				return DXGI_FORMAT_R16G16_UNORM;
			}

			if (ISBITMASK(0xffffffff, 0x00000000, 0x00000000, 0x00000000))
			{
				// Only 32-bit color channel format in D3D9 was R32F
				return DXGI_FORMAT_R32_FLOAT; // D3DX writes this out as a FourCC of 114
			}
			break;

		case 24:
			// No 24bpp DXGI formats aka D3DFMT_R8G8B8
			break;

		case 16:
			if (ISBITMASK(0x7c00, 0x03e0, 0x001f, 0x8000))
			{
				return DXGI_FORMAT_B5G5R5A1_UNORM;
			}
			if (ISBITMASK(0xf800, 0x07e0, 0x001f, 0x0000))
			{
				return DXGI_FORMAT_B5G6R5_UNORM;
			}

			// No DXGI format maps to ISBITMASK(0x7c00,0x03e0,0x001f,0x0000) aka D3DFMT_X1R5G5B5

			if (ISBITMASK(0x0f00, 0x00f0, 0x000f, 0xf000))
			{
				return DXGI_FORMAT_B4G4R4A4_UNORM;
			}

			// No DXGI format maps to ISBITMASK(0x0f00,0x00f0,0x000f,0x0000) aka D3DFMT_X4R4G4B4

			// No 3:3:2, 3:3:2:8, or paletted DXGI formats aka D3DFMT_A8R3G3B2, D3DFMT_R3G3B2, D3DFMT_P8, D3DFMT_A8P8, etc.
			break;
		}
	}
	else if (ddpf.flags & DDS_LUMINANCE)
	{
		if (8 == ddpf.RGBBitCount)
		{
			if (ISBITMASK(0x000000ff, 0x00000000, 0x00000000, 0x00000000))
			{
				return DXGI_FORMAT_R8_UNORM; // D3DX10/11 writes this out as DX10 extension
			}

			// No DXGI format maps to ISBITMASK(0x0f,0x00,0x00,0xf0) aka D3DFMT_A4L4
		}

		if (16 == ddpf.RGBBitCount)
		{
			if (ISBITMASK(0x0000ffff, 0x00000000, 0x00000000, 0x00000000))
			{
				return DXGI_FORMAT_R16_UNORM; // D3DX10/11 writes this out as DX10 extension
			}
			if (ISBITMASK(0x000000ff, 0x00000000, 0x00000000, 0x0000ff00))
			{
				return DXGI_FORMAT_R8G8_UNORM; // D3DX10/11 writes this out as DX10 extension
			}
		}
	}
	else if (ddpf.flags & DDS_ALPHA)
	{
		if (8 == ddpf.RGBBitCount)
		{
			return DXGI_FORMAT_A8_UNORM;
		}
	}
	else if (ddpf.flags & DDS_FOURCC)
	{
		if (MAKEFOURCC('D', 'X', 'T', '1') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC1_UNORM;
		}
		if (MAKEFOURCC('D', 'X', 'T', '3') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC2_UNORM;
		}
		if (MAKEFOURCC('D', 'X', 'T', '5') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC3_UNORM;
		}

		// While pre-multiplied alpha isn't directly supported by the DXGI formats,
		// they are basically the same as these BC formats so they can be mapped
		if (MAKEFOURCC('D', 'X', 'T', '2') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC2_UNORM;
		}
		if (MAKEFOURCC('D', 'X', 'T', '4') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC3_UNORM;
		}

		if (MAKEFOURCC('A', 'T', 'I', '1') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC4_UNORM;
		}
		if (MAKEFOURCC('B', 'C', '4', 'U') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC4_UNORM;
		}
		if (MAKEFOURCC('B', 'C', '4', 'S') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC4_SNORM;
		}

		if (MAKEFOURCC('A', 'T', 'I', '2') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC5_UNORM;
		}
		if (MAKEFOURCC('B', 'C', '5', 'U') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC5_UNORM;
		}
		if (MAKEFOURCC('B', 'C', '5', 'S') == ddpf.fourCC)
		{
			return DXGI_FORMAT_BC5_SNORM;
		}

		// BC6H and BC7 are written using the "DX10" extended header

		if (MAKEFOURCC('R', 'G', 'B', 'G') == ddpf.fourCC)
		{
			return DXGI_FORMAT_R8G8_B8G8_UNORM;
		}
		if (MAKEFOURCC('G', 'R', 'G', 'B') == ddpf.fourCC)
		{
			return DXGI_FORMAT_G8R8_G8B8_UNORM;
		}

		if (MAKEFOURCC('Y', 'U', 'Y', '2') == ddpf.fourCC)
		{
			return DXGI_FORMAT_YUY2;
		}

		// Check for D3DFORMAT enums being set here
		switch (ddpf.fourCC)
		{
		case 36: // D3DFMT_A16B16G16R16
			return DXGI_FORMAT_R16G16B16A16_UNORM;

		case 110: // D3DFMT_Q16W16V16U16
			return DXGI_FORMAT_R16G16B16A16_SNORM;

		case 111: // D3DFMT_R16F
			return DXGI_FORMAT_R16_FLOAT;

		case 112: // D3DFMT_G16R16F
			return DXGI_FORMAT_R16G16_FLOAT;

		case 113: // D3DFMT_A16B16G16R16F
			return DXGI_FORMAT_R16G16B16A16_FLOAT;

		case 114: // D3DFMT_R32F
			return DXGI_FORMAT_R32_FLOAT;

		case 115: // D3DFMT_G32R32F
			return DXGI_FORMAT_R32G32_FLOAT;

		case 116: // D3DFMT_A32B32G32R32F
			return DXGI_FORMAT_R32G32B32A32_FLOAT;
		}
	}

	return DXGI_FORMAT_UNKNOWN;
}


//--------------------------------------------------------------------------------------
static DXGI_FORMAT MakeSRGB(_In_ DXGI_FORMAT format)
{
	switch (format)
	{
	case DXGI_FORMAT_R8G8B8A8_UNORM:
		return DXGI_FORMAT_R8G8B8A8_UNORM_SRGB;

	case DXGI_FORMAT_BC1_UNORM:
		return DXGI_FORMAT_BC1_UNORM_SRGB;

	case DXGI_FORMAT_BC2_UNORM:
		return DXGI_FORMAT_BC2_UNORM_SRGB;

	case DXGI_FORMAT_BC3_UNORM:
		return DXGI_FORMAT_BC3_UNORM_SRGB;

	case DXGI_FORMAT_B8G8R8A8_UNORM:
		return DXGI_FORMAT_B8G8R8A8_UNORM_SRGB;

	case DXGI_FORMAT_B8G8R8X8_UNORM:
		return DXGI_FORMAT_B8G8R8X8_UNORM_SRGB;

	case DXGI_FORMAT_BC7_UNORM:
		return DXGI_FORMAT_BC7_UNORM_SRGB;

	default:
		return format;
	}
}


//--------------------------------------------------------------------------------------
static HRESULT FillInitData(_In_ size_t width,
	_In_ size_t height,
	_In_ size_t depth,
	_In_ size_t mipCount,
	_In_ size_t arraySize,
	_In_ DXGI_FORMAT format,
	_In_ size_t maxsize,
	_In_ size_t bitSize,
	_In_reads_bytes_(bitSize) const uint8_t* bitData,
	_Out_ size_t& twidth,
	_Out_ size_t& theight,
	_Out_ size_t& tdepth,
	_Out_ size_t& skipMip,
	_Out_writes_(mipCount* arraySize) D3D11_SUBRESOURCE_DATA* initData)
{
	if (!bitData || !initData)
	{
		return E_POINTER;
	}

	skipMip = 0;
	twidth = 0;
	theight = 0;
	tdepth = 0;

	size_t NumBytes = 0;
	size_t RowBytes = 0;
	const uint8_t* pSrcBits = bitData;
	const uint8_t* pEndBits = bitData + bitSize;

	size_t index = 0;
	for (size_t j = 0; j < arraySize; j++)
	{
		size_t w = width;
		size_t h = height;
		size_t d = depth;
		for (size_t i = 0; i < mipCount; i++)
		{
			GetSurfaceInfo(w,
				h,
				format,
				&NumBytes,
				&RowBytes,
				nullptr
			);

			if ((mipCount <= 1) || !maxsize || (w <= maxsize && h <= maxsize && d <= maxsize))
			{
				if (!twidth)
				{
					twidth = w;
					theight = h;
					tdepth = d;
				}

				assert(index < mipCount* arraySize);
				_Analysis_assume_(index < mipCount* arraySize);
				initData[index].pSysMem = (const void*)pSrcBits;
				initData[index].SysMemPitch = static_cast<UINT>(RowBytes);
				initData[index].SysMemSlicePitch = static_cast<UINT>(NumBytes);
				++index;
			}
			else if (!j)
			{
				// Count number of skipped mipmaps (first item only)
				++skipMip;
			}

			if (pSrcBits + (NumBytes * d) > pEndBits)
			{
				return HRESULT_FROM_WIN32(ERROR_HANDLE_EOF);
			}

			pSrcBits += NumBytes * d;

			w = w >> 1;
			h = h >> 1;
			d = d >> 1;
			if (w == 0)
			{
				w = 1;
			}
			if (h == 0)
			{
				h = 1;
			}
			if (d == 0)
			{
				d = 1;
			}
		}
	}

	return (index > 0) ? S_OK : E_FAIL;
}

static HRESULT FillInitData12(_In_ size_t width,
	_In_ size_t height,
	_In_ size_t depth,
	_In_ size_t mipCount,
	_In_ size_t arraySize,
	_In_ DXGI_FORMAT format,
	_In_ size_t maxsize,
	_In_ size_t bitSize,
	_In_reads_bytes_(bitSize) const uint8_t* bitData,
	_Out_ size_t& twidth,
	_Out_ size_t& theight,
	_Out_ size_t& tdepth,
	_Out_ size_t& skipMip,
	_Out_writes_(mipCount* arraySize) D3D12_SUBRESOURCE_DATA* initData
)
{
	if (!bitData || !initData)
	{
		return E_POINTER;
	}

	skipMip = 0;
	twidth = 0;
	theight = 0;
	tdepth = 0;

	size_t NumBytes = 0;
	size_t RowBytes = 0;
	const uint8_t* pSrcBits = bitData;
	const uint8_t* pEndBits = bitData + bitSize;

	size_t index = 0;
	for (size_t j = 0; j < arraySize; j++)
	{
		size_t w = width;
		size_t h = height;
		size_t d = depth;
		for (size_t i = 0; i < mipCount; i++)
		{
			GetSurfaceInfo(w,
				h,
				format,
				&NumBytes,
				&RowBytes,
				nullptr
			);

			if ((mipCount <= 1) || !maxsize || (w <= maxsize && h <= maxsize && d <= maxsize))
			{
				if (!twidth)
				{
					twidth = w;
					theight = h;
					tdepth = d;
				}

				assert(index < mipCount* arraySize);
				_Analysis_assume_(index < mipCount* arraySize);
				initData[index]./*pSysMem*/pData = (const void*)pSrcBits;
				initData[index]./*SysMemPitch*/RowPitch = static_cast<UINT>(RowBytes);
				initData[index]./*SysMemSlicePitch*/SlicePitch = static_cast<UINT>(NumBytes);
				++index;
			}
			else if (!j)
			{
				// Count number of skipped mipmaps (first item only)
				++skipMip;
			}

			if (pSrcBits + (NumBytes * d) > pEndBits)
			{
				return HRESULT_FROM_WIN32(ERROR_HANDLE_EOF);
			}

			pSrcBits += NumBytes * d;

			w = w >> 1;
			h = h >> 1;
			d = d >> 1;
			if (w == 0)
			{
				w = 1;
			}
			if (h == 0)
			{
				h = 1;
			}
			if (d == 0)
			{
				d = 1;
			}
		}
	}

	return (index > 0) ? S_OK : E_FAIL;
}



static HRESULT CreateTextureInitData(
	_In_ const DDS_HEADER* header,
	_In_reads_bytes_(bitSize) const uint8_t* bitData,
	_In_ size_t bitSize,
	_In_ size_t maxsize,
	_In_ bool forceSRGB,
	TTextureInfo& TextureInfo,
	std::vector<D3D12_SUBRESOURCE_DATA>& initData
)
{
	HRESULT hr = S_OK;

	UINT width = header->width;
	UINT height = header->height;
	UINT depth = header->depth;

	uint32_t resDim = D3D12_RESOURCE_DIMENSION_UNKNOWN;
	UINT arraySize = 1;
	DXGI_FORMAT format = DXGI_FORMAT_UNKNOWN;
	bool isCubeMap = false;

	size_t mipCount = header->mipMapCount;
	if (0 == mipCount) mipCount = 1;

	if ((header->ddspf.flags & DDS_FOURCC) && (MAKEFOURCC('D', 'X', '1', '0') == header->ddspf.fourCC))
	{
		auto d3d10ext = reinterpret_cast<const DDS_HEADER_DXT10*>((const char*)header + sizeof(DDS_HEADER));

		arraySize = d3d10ext->arraySize;
		if (arraySize == 0)
			return HRESULT_FROM_WIN32(ERROR_INVALID_DATA);

		switch (d3d10ext->dxgiFormat)
		{
		case DXGI_FORMAT_AI44:
		case DXGI_FORMAT_IA44:
		case DXGI_FORMAT_P8:
		case DXGI_FORMAT_A8P8:
			return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);

		default:
			if (BitsPerPixel(d3d10ext->dxgiFormat) == 0)
				return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
		}

		format = d3d10ext->dxgiFormat;

		switch (d3d10ext->resourceDimension)
		{
		case D3D11_RESOURCE_DIMENSION_TEXTURE1D:
			if ((header->flags & DDS_HEIGHT) && height != 1)
				return HRESULT_FROM_WIN32(ERROR_INVALID_DATA);
			height = depth = 1;
			break;

		case D3D11_RESOURCE_DIMENSION_TEXTURE2D:
			if (d3d10ext->miscFlag & D3D11_RESOURCE_MISC_TEXTURECUBE)
			{
				arraySize *= 6;
				isCubeMap = true;
			}
			depth = 1;
			break;

		case D3D11_RESOURCE_DIMENSION_TEXTURE3D:
			if (!(header->flags & DDS_HEADER_FLAGS_VOLUME))
				return HRESULT_FROM_WIN32(ERROR_INVALID_DATA);
			if (arraySize > 1)
				return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
			break;

		default:
			return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
		}

		switch (d3d10ext->resourceDimension)
		{
		case D3D11_RESOURCE_DIMENSION_TEXTURE1D:
			resDim = D3D12_RESOURCE_DIMENSION_TEXTURE1D;
			break;
		case D3D11_RESOURCE_DIMENSION_TEXTURE2D:
			resDim = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
			break;
		case D3D11_RESOURCE_DIMENSION_TEXTURE3D:
			resDim = D3D12_RESOURCE_DIMENSION_TEXTURE3D;
			break;
		}
	}
	else
	{
		format = GetDXGIFormat(header->ddspf);

		if (format == DXGI_FORMAT_UNKNOWN)
			return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);

		if (header->flags & DDS_HEADER_FLAGS_VOLUME)
		{
			resDim = D3D12_RESOURCE_DIMENSION_TEXTURE3D;
		}
		else
		{
			if (header->caps2 & DDS_CUBEMAP)
			{
				if ((header->caps2 & DDS_CUBEMAP_ALLFACES) != DDS_CUBEMAP_ALLFACES)
					return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
				arraySize = 6;
				isCubeMap = true;
			}

			depth = 1;
			resDim = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
		}

		assert(BitsPerPixel(format) != 0);
	}

	// Bound sizes (for security purposes we don't trust DDS file metadata larger than the D3D 11.x hardware requirements)
	if (mipCount > D3D12_REQ_MIP_LEVELS)
	{
		return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
	}

	switch (resDim)
	{
	case D3D12_RESOURCE_DIMENSION_TEXTURE1D:
		if ((arraySize > D3D12_REQ_TEXTURE1D_ARRAY_AXIS_DIMENSION) ||
			(width > D3D12_REQ_TEXTURE1D_U_DIMENSION))
		{
			return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
		}
		break;

	case D3D12_RESOURCE_DIMENSION_TEXTURE2D:
		if (isCubeMap)
		{
			// This is the right bound because we set arraySize to (NumCubes*6) above
			if ((arraySize > D3D12_REQ_TEXTURE2D_ARRAY_AXIS_DIMENSION) ||
				(width > D3D12_REQ_TEXTURECUBE_DIMENSION) ||
				(height > D3D12_REQ_TEXTURECUBE_DIMENSION))
			{
				return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
			}
		}
		else if ((arraySize > D3D12_REQ_TEXTURE2D_ARRAY_AXIS_DIMENSION) ||
			(width > D3D12_REQ_TEXTURE2D_U_OR_V_DIMENSION) ||
			(height > D3D12_REQ_TEXTURE2D_U_OR_V_DIMENSION))
		{
			return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
		}
		break;

	case D3D12_RESOURCE_DIMENSION_TEXTURE3D:
		if ((arraySize > 1) ||
			(width > D3D12_REQ_TEXTURE3D_U_V_OR_W_DIMENSION) ||
			(height > D3D12_REQ_TEXTURE3D_U_V_OR_W_DIMENSION) ||
			(depth > D3D12_REQ_TEXTURE3D_U_V_OR_W_DIMENSION))
		{
			return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
		}
		break;

	default:
		return HRESULT_FROM_WIN32(ERROR_NOT_SUPPORTED);
	}

	if (forceSRGB)
	{
		format = MakeSRGB(format);
	}


	// Create the texture
	initData.resize(mipCount * arraySize);

	size_t skipMip = 0;
	size_t twidth = 0;
	size_t theight = 0;
	size_t tdepth = 0;

	hr = FillInitData12(
		width, height, depth, mipCount, arraySize, format, maxsize, bitSize, bitData,
		twidth, theight, tdepth, skipMip, initData.data()
	);

	TextureInfo.ArraySize = arraySize;
	TextureInfo.Format = format;
	TextureInfo.Width = width;
	TextureInfo.Height = height;
	TextureInfo.Depth = depth;
	TextureInfo.MipCount = mipCount;
	TextureInfo.Dimension = (D3D12_RESOURCE_DIMENSION)resDim;

	return hr;
}



//--------------------------------------------------------------------------------------
static DDS_ALPHA_MODE GetAlphaMode(_In_ const DDS_HEADER* header)
{
	if (header->ddspf.flags & DDS_FOURCC)
	{
		if (MAKEFOURCC('D', 'X', '1', '0') == header->ddspf.fourCC)
		{
			auto d3d10ext = reinterpret_cast<const DDS_HEADER_DXT10*>((const char*)header + sizeof(DDS_HEADER));
			auto mode = static_cast<DDS_ALPHA_MODE>(d3d10ext->miscFlags2 & DDS_MISC_FLAGS2_ALPHA_MODE_MASK);
			switch (mode)
			{
			case DDS_ALPHA_MODE_STRAIGHT:
			case DDS_ALPHA_MODE_PREMULTIPLIED:
			case DDS_ALPHA_MODE_OPAQUE:
			case DDS_ALPHA_MODE_CUSTOM:
				return mode;
			}
		}
		else if ((MAKEFOURCC('D', 'X', 'T', '2') == header->ddspf.fourCC)
			|| (MAKEFOURCC('D', 'X', 'T', '4') == header->ddspf.fourCC))
		{
			return DDS_ALPHA_MODE_PREMULTIPLIED;
		}
	}

	return DDS_ALPHA_MODE_UNKNOWN;
}


_Use_decl_annotations_
HRESULT DirectX::CreateDDSTextureFromFile(
	const wchar_t* szFileName,
	TTextureInfo& TextureInfo,
	std::vector<D3D12_SUBRESOURCE_DATA>& initData,
	std::vector<uint8_t>& ddsData,
	bool forceSRGB,
	size_t maxsize,
	DDS_ALPHA_MODE* alphaMode)
{
	if (alphaMode)
	{
		*alphaMode = DDS_ALPHA_MODE_UNKNOWN;
	}

	if (!szFileName)
	{
		return E_INVALIDARG;
	}

	DDS_HEADER* header = nullptr;
	uint8_t* bitData = nullptr;
	size_t bitSize = 0;

	//std::unique_ptr<uint8_t[]> ddsData;
	HRESULT hr = LoadTextureDataFromFile(szFileName, ddsData, &header, &bitData, &bitSize);
	if (FAILED(hr))
	{
		return hr;
	}

	hr = CreateTextureInitData(header, bitData, bitSize, maxsize, forceSRGB, TextureInfo, initData);

	if (SUCCEEDED(hr))
	{
		if (alphaMode)
			*alphaMode = GetAlphaMode(header);
	}

	return hr;
}
